REDUCED SMOOTH-MUSCLE CELL REGENERATION IN YOSHIDA (YOS) SPONTANEOUSLY HYPERCHOLESTEROLEMIC RATS

Hypercholesterolemia is a predisposing factor for atherosclerosis. We studied the response to damage of vascular smooth muscle cells (SMC) f rom normocholesterolemic Brown Norway (BN) and from spontaneously hype rcholesterolemic Yoshida (YOS) rats (16-24 month old). The regrowth ra te of SMC from BN and YOS rats after freeze-induced damage was similar in the presence of fetal calf serum and of serum derived from normoch olesterolemic rats, while it was reduced in the presence of serum from hypercholesterolemic rats. Freeze-injury of the abdominal aorta was f ollowed by reduced neointima formation in YOS rats, as compared to BN rats, confirming the impaired response of vascular cells from hypercho lesterolemic rats to injury. This defect may be due either to lipids o r to unknown factors present in the hyperlypidemic serum.